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Increasing demand for clean, globally available energy, provokes the development of alternative or nonconventional energy storage sources with higher energy density and power delivery. Therefore, supercapacitors have received great attention in both academic and industrial research. In addition, supercapacitors are promising new sources of energy in the future energy technology. Hence, rapid progress has been made to understand their fundamentals and applicable aspects. Supercapacitors, also known as ultracapacitors, bridge the gap between batteries and con- ventional capacitors, which means that supercapacitors can accept and deliver charge much faster than batteries, and can store 10 to 100 times more energy per unit volume than fuel cells. Su- percapacitors are well known not only because of their huge energy density, but also due to their long shelf and good cyclic ability. The particular properties of supercapacitors are due to utiliza- tion of electrode materials with very high porosity, and also the specific mechanism of charge storage. In general, there are two fundamental chemical and physical mechanisms for energy storage. In chemical mechanism the charges are released through oxidation-reduction reaction. However, in the physical mechanism the electrical energy is stored physically with electrostatic interaction, while no chemical and phase changes occur. Hence, according to theses charge storage mechanisms supercapacitors are divided into three main groups: electric double layer capacitors (EDLCs), pseudocapacitors and hybrid capacitors. Each of these supercapacitors has its own ad- vantages and disadvantages. These three different kind of supercacaitors are distinguished by their charge storage mechanism and also their electrode materials. Electrical double layer capacitors store the charge based on physical mechanism, and also various types of carbon are used as electrode material. Pseudocapacitors save energy via electro- chemical redox reactions. Besides, these capacitors utilize metal oxides and conducting polymers as electrode material. Hybrid capacitors are another class of supercapacitors, which are constructed of two different types of electrode materials. Therefore, the mechanism of energy storage is a com- bination of both chemical and physical mechanisms. The most used electrode materials in these supercapacitors are a composition of carbon-based materials with either conducting polymers or metal oxide materials. In this work electrical double layer capacitors have captured our attention because of both their interesting energy storage mechanism and also their electrode materials. Electrode material is one of the most important factors in the performance of an electro- chemical energy storage device. Therefore, innovation of new electrode materials is one of the most attractive topics in recent investigations. Especially carbon based electrodes such as carbon nanofibers, activated carbon, carbon nanotubes (CNTs) etc. with their porous structure can pro- vide very huge surface area, consequently immense capacity. Among the examined carbon based materials carbon nanotubes are one of the most interesting because of their unique physical and chemical properties. In fact, special properties of carbon nanotubes such as individual tubular structure, very high chemical stability, low resistivity, high thermal and electrical conductivity and enormous surface area make them good candidates for electrode material in electrical double layer capacitors. Carbon nanotubes are divided into three main groups such as zigzag, armchair and chi- ral tubes. Based on their electronic structure, carbon nanotubes can have metallic or semimetallic characteristic. As mentioned above the huge capacity of carbon materials is due to their massive surface area. Furthermore, in the case of carbon nanotubes both the inner and outer walls can be available for electrolyte ions. At first it was thought, that very narrow pores do not participate in the forma- tion of double layer and energy storage. However, experimental investigations proved, that very narrow pores (lower than 1nm size) not only participate in energy storage, but also exhibit an enor- mous increase of capacitance. Later, theoretical findings showed that the image charge between ion and pore wall screen the repulsion between the ions. This leads to a denser packing of ions, consequently increasing the electrode capacitance. In this work we have studied ion intercalation into carbon nanotubes with diameters lower than 1nm as electrode material by density functional theory. All the calculations have been done using the VASP package. The idea of this work is in that we have imagined carbon nanotubes as electrode materials immersed in solution. Hence, the electrolyte ions try to penetrate into the carbon nanotubes. This work is divided into four parts, which are as follows: In the first part, we have selected truncated carbon nanotubes or carbon nanorings, whoese ends are saturated with hydrogen atoms. In particular, the truncated carbon nanotubes are include the (6,0), (8,0), (10,0) and (12,0) carbon nanotubes. As electrolyte ions alkali (Li, Na and Cs) and halogen (Cl, Br and I) atoms have been tried. Meanwhile, we have neglected the presence of solvent or any counterpart. After simulation it was realized that all the alkali atoms have lost one electron, and also the halogen atoms have obtained one more electron, and also the stable position of all the ions is in the center of the tubes. The results have shown that the surrounding tubes screen the ionic charge very effectively, thereby the ion-ion interactions are strongly reduced, which explains, why narrow tubes store charge more effectively than wider one. We have calculated the insertion energies of the atoms into the tubes and understood that for each atom the diameter of the tube has to be optimized. In the second part of the work, we extended the model of short nanotubes to infinite ones. In particular, we have chosen the (6,2)CNT, the (6,3)CNT, the (8,0)CNT and the (5,5)CNT as electrode material. Among the presented carbon nanotubes the (6,2)CNT and the (8,0)CNT are semimetallic, while the (5,5)CNT and the (6,3)CNT are metallic. Like in the previous work we have inserted alkali (Li, Na and Cs) and halogen (F, Cl, Br and I) atoms into the carbon nanotubes. The results have shown that the atoms were fully ionized. The charge exchange with the CNTs affects the band structure, and turns those tubes that were originally semiconductors into conductors. None of the ions is adsorbed chemically, their position inside the tube and their energies of adsorption are determined by a competition between electrostatic image interactions, which favor a position at the wall, and Pauli repulsion. In models for charge storage it is often assumed that in small tubes the ions are at the center, but we have found several cases where small alkali ions are positioned near the wall. We have also investigated the screening of the Coulomb potential along the axis of the tubes. In particular we wanted to see if there is a difference between semiconducting and conducting CNTs. Within the accuracy of our calculations we found no difference in the screening, because the charge transfer has made the non-chiral tubes conducting. In the third part of this work, we have investigated insertion of alkali and halogen atoms into nitrogen doped (N-doped) carbon nanotubes. Here, the (8,0)CNT and the (5,5)CNT have been chosen as electrode material. The results have shown that N-doped carbon nanotubes are less stable than the pure ones, and also the atoms were fully ionized. The position of the ions in the carbon nanotubes exhibits contradictory behavior in the (8,0)CNT than the (5,5)CNT. In fact, in the former one the ions have high repulsion from the impurity area and try to get away as far as possible. This effect is stronger in the case of small ions like Li+. However, in the (5,5)CNT the ions get closer to the nitrogen area. This behavior is caused by the difference in the spin density of carbon nanotubes. In other words, the spin density is more localized in the N-doped (8,0)CNT than the N- doped (5,5)CNT. Therefore, it causes big repulsion with the inserted ions. The nitrogen doping and charge exchange with ions affect the band structure of carbon nanotubes. Actually, substitution of nitrogen and insertion of alkali atom keep the tubes conducting. However, intercalation of halogen atoms causes both tubes to become semiconducting. We also have calculated insertion energy of ions in the N-doped carbon nanotubes. The results have shown that insertion of the ions is more favorable in the N-doped carbon nanotubes than in the pure ones. In the fourth part of the work, we have taken into account the presence of counterions. For this purpose we have tried insertion of alkali halide monomers (LiF, LiCl and NaCl), a chain of NaCl in nanotube, as well as presence of water molecules with NaCl monomer in a carbon nanotube. Therefore, the (5,5)CNT as electrode material has been chosen. In all the investigated systems, the ions and the molecules are not chemically bound to the carbon nanotube wall. In the case of alkali halide monomers there is no strong charge transfer with the nanotube. However, for the chain of NaCl this interaction is stronger, while the main charge transfer is between the alkali and halide ions in the chain. Water does not exchange charge with the nanotube. Nonetheless, it tries to hydrate the alkali and halide ions confined in the tube.

We study the effect of early life exposure to above average levels of rainfall on adult mental health. While we find no effect from pre-natal exposure, post-natal positive rainfall shocks decrease average Center for Epidemiological Studies Depression (CESD) mental health scores by 15 percent and increase the likelihood of depression by 5 percent, a more than 20 percent increase relative to the mean. These effects are limited to females. We rule out prenatal stress and income shocks as pathways and find evidence suggestive of increased exposure to disease. CINCH working paper series, vol. 2018, no. 5

Strontium- and magnesium-doped lanthanum gallate (LSGM) perovskite-type compounds and doped ceria-based materials have recently been considered the most promising solid electrolytes for intermediate temperature solid oxide fuel cell (IT-SOFC) applications. While nickel metal is commonly used for the fabrication of cermet-type anodes, the rare earth nickelates, such as Sr-doped La2NiO4 (LSN), are recently developed high-performance cathode materials. For successful implementation in IT-SOFC, it is therefore essential to know the phase equilibria and thermodynamic properties for systems representing the solid electrolyte and electrode materials across their various combinations. This thesis aims to determine the phase equilibria and the thermodynamics of the relevant phases in the systems La-Sr-Ga-Mg-Ni-O, Ce-Gd-Sr-Ni-O, and Ce-Gd-La-Ni-O. Subsystems of these multi-component systems were thermodynamically modeled, based on the available literature and experimental data obtained from this work. The experimental studies were designed based on the calculated phase diagrams. A minimum number of compositions was chosen strategically to obtain a preliminary prediction of the phases in equilibrium in each constituent subsystem. Finally, the experimental and computational results were used to predict the compatibility/reactivity of IT-SOFC components under fabrication and/or operation conditions. Various experimental techniques were employed for determination of the phase equilibria such as Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray analysis (EDX), X-ray Diffraction (XRD), Differential Scanning and Adiabatic Calorimetry, and Mass Spectrometry (MS). The CALPHAD-method (CALculation of PHAse Diagrams) and THERMOCALC software were used to obtain self-consistent sets of Gibbs energy functions. The following systems were investigated experimentally: La-Ni-O, La-Ga-Ni-O, La-Sr-Ni-O, La-Mg-Ni-O, La-Ga-Mg-Ni-O, La-Sr-Ga-Ni-O, La-Sr-Ga-Mg-Ni-O, Ce-Ni-O, Ce-Sr-O, Gd-Ni-O, Gd-Sr-O, Ce-Gd-Ni-O, Ce-Gd-Sr-O, Ce-Sr-Ni-O, Gd-Sr-Ni-O, Ce-Gd-Sr-Ni-O and Ce-Gd-La-Ni-O. Using results from this experimental work and data from the literature, the following systems were thermodynamically modeled: La-Ni-O, La-Ga-Ni-O, La-Sr-Ni-O, La-Mg-Ni-O, Ce-Ni-O, Ce-Sr-O, Gd-Ni-O and Gd-Sr-O. The systems, La-Ga-Mg-Ni-O, La-Sr-Ga-Ni-O, and Ce-Gd-Ni-O were extrapolated using parameters optimized from the constituent lower-order systems. In the La-Ni-O system, the enthalpy of formation, entropy and heat capacity of La3Ni2O7, La4Ni3O10, and LaNiO3, were determined experimentally for the first time using equilibration with the gas phase, adiabatic calorimetry and differential scanning calorimetry. In the La-Ga-Ni-O, La-Sr-Ni-O and La-Mg-Ni-O systems, extended solid solutions of La(Ga,Ni)O3, La2(Ni,Ga)O4, La4(Ni,Ga)3O10, (La,Sr)2NiO4, and La2(Ni,Mg)O4 were found, and the limits of their homogeneity ranges have been established for the first time. In addition, the compound LaNiGa11O19, with a magnetoplumbite-type structure was identified, which has not been reported in the literature to date. In the La-Ga-Mg-Ni-O system, the temperature dependence of the quasi-quaternary homogeneity range of La(Ga,Mg,Ni)O3 was determined. In the La-Sr-Ga-Ni-O system, a reaction was observed between LaGaO3 and LaSrNiO4 that formed a melilite-type La1-xSr1+xGa3O7+z, LaGaSrO4 and NiO phase. Similar reaction mechanisms were observed in the La-Sr-Ga-Mg-Ni-O system. Experiments in the Ce-Ni-O system were conducted in air as well as in a reducing atmosphere. It has been found that NiO does not react with CeO2. In the Ce-Sr-O system, the entropy and heat capacity of Sr2CeO4 were experimentally determined for the first time. In the Gd-Ni-O system a eutectic reaction was observed (liquid <=> B-Gd2O3 + NiO). The Gd-Sr-O system was modeled thermodynamically based on data from the literature and the experimentally determined homogeneity range on the Gd2O3-rich site. In the Ce-Sr-Ni-O system the solid solution of (Ce,Sr)2NiO4-z was determined. No reaction between NiO and SrCeO3 / Sr2CeO4 was found. Similarly, in the Ce-Gd-Ni-O system, no reaction was observed between (Ce,Gd)O2-z and NiO. In contrast, solid solutions of Sr(Ce,Gd)O3, Sr2(Ce,Gd)O4 and (Gd,Sr)2(Sr,Ce)O4 were determined in the Ce-Gd-Sr-O system. Also, an extended solid solution of (Gd,Sr)2NiO4 was found in the Gd-Sr-Ni-O system that does not exist in the quasi-binary sections, but is stable in higher-order systems only because a solid solution is formed. It has been also found that there is no NiO solubility in the Gd2SrO4 phase. It could be concluded that doped ceria-based materials are chemically compatible with NiO during conditions typical for both the fabrication and the operation of IT-SOFC’s, whereas LSGM-type electrolytes react with NiO under the fuel cell fabrication conditions. Moreover, although La2NiO4 is a high-performance cathode, it cannot be used in combination with LSGM- or CGO-type electrolytes, due to its reactivity with both of these materials under fabrication conditions. Strontium- und Magnesium- dotierte Lanthangallat Verbindungen des Perowskit-Typs und dotierte Ceroxid-basierte Materialien (DC) wurden kürzlich als hoffnungsvolle Festelektrolyte für die Festoxidbrennstoffzelle bei intermediärer Temperatur (IT-SOFC) betrachtet. Normalerweise wird metallisches Nickel zur Herstellung der Komposit-Anode verwendet, wobei neuerdings die Nickelate von Seltenerdmetallen, wie z.B. Sr-dotierte La2NiO4 (LSN), zur Hochleistungskathode entwickelt werden. Um IT-SOFC erfolgreich herzustellen und auszunutzen sind die Kenntnisse der Phasengleichgewichten und Thermodynamik für Systeme notwendig, welche die Kathoden, Festelektrolyt, Anoden und ihre mögliche Kombinationen repräsentieren. Ziel der Arbeit ist die Phasengleichgewichten und Thermodynamik von La-Sr-Ga-Mg-Ni-O, Ce-Gd-Sr-Ni-O und Ce-Gd-La-Ni-O Systeme zu bestimmen. Die Subsysteme wurden thermodynamisch berechnet auf der Basis von Literaturdaten, während die experimentelle Untersuchungen durch berechnete Phasendiagramm entworfen wurden, wodurch weniger Aufwand benötigt wurde. Schließlich wurden die experimentellen und rechnerischen Ergebnisse verwendet, um die Kompatibilität und Reaktivität von IT-SOFC Komponenten unter Herstellung- und Arbeitsbedingungen vorauszusagen. Für die experimentelle Bestimung der Phasengleichgewichte der Systeme wurden verschiedene Untersuchungsmethoden verwendet, wie z.B. Rasterelektronmikroskopie (REM), Energiedispersive Röntgenspektroskopie (EDX), Dynamische Differenzkalorimetrie und Thermogravimetrie. Die CALPHAD-Methode (Calculation of PHAse Diagrams) mit THERMOCALC Software wurde auch verwendet, um eine selbstkonsequente Reihe von freien Enthalpie Funktionen zu bekommen. Die folgenden Systeme wurden experimentell untersucht: La-Ni-O, La-Ga-Ni-O, La-Sr-Ni-O, La-Mg-Ni-O, La-Ga-Mg-Ni-O, La-Sr-Ga-Ni-O, La-Sr-Ga-Mg-Ni-O, Ce-Ni-O, Ce-Sr-O, Gd-Ni-O, Gd-Sr-O, Ce-Gd-Ni-O, Ce-Gd-Sr-O, Ce-Sr-Ni-O, Gd-Sr-Ni-O, Ce-Gd-Sr-Ni-O, Ce-Gd-La-Ni-O. Durch erhaltenen Ergebnisse und Literaturdaten wurden thermodynamische Modelle für die folgenden Systemen gestellt: La-Ni-O, La-Ga-Ni-O, La-Sr-Ni-O, La-Mg-Ni-O, Ce-Ni-O, Ce-Sr-O, Gd-Ni-O, Gd-Sr-O. Mit optimierte Parameter von Systemen niedrigerer Ordnung wurden die Systeme La-Ga-Mg-Ni-O, La-Sr-Ga-Ni-O, und Ce-Gd-Ni-O extrapoliert. Im La-Ni-O System wurden die Bildungsenthalpie, Entropie und Wärmekapazität von La3Ni2O7, La4Ni3O10 und LaNiO3 durch Gleichgewicht mit Gasphase, adiabatische Kalorimetrie und Dynamische Differenzkalorimetrie experimentell bestimmt. In den La-Ga-Ni-O, La-Sr-Ni-O, La-Mg-Ni-O Systeme wurden erweiterten Mischkristalle La(Ga,Ni)O3, La2(Ni,Ga)O4, La4(Ni,Ga)3O10, (La,Sr)2NiO4 und La2(Ni,Mg)O4 gefunden und ihre Homogenitätsbereichen bestimmt. Zusätzlich wurden die Magnetoplumbite-Typ Verbindung LaNiGa11O19 gefunden, die bislang noch nicht in der Literaturen bekannt war. Im La-Ga-Mg-Ni-O System wurde die Temperaturabhängigkeit von La(Ga,Mg,Ni)O3 Homogenitätsbereich untersucht. Im La-Sr-Ga-Ni-O System wurde eine Reaktion zwischen LaGaO3 und LaSrNiO4 untersucht, die Melilite-Typ La1-xSr1+xGa3O7+z, LaGaSrO4 und NiO bildet. Der gleiche Reaktionsmechanismus wurde auch im La-Sr-Ga-Mg-Ni-O System beobachtet. Die Experimente für Ce-Ni-O System wurden sowohl an Luft als auch im Reduktions- Atmosphäre durchgeführt. Es wurde gefunden, dass NiO nicht mit CeO2 reagiert. Für Ce-Sr-O System wurden zuerst die Entropie und Wärmekapazität von Sr2CeO4 experimentell bestimmt. Für Gd-Ni-O System wurde eine eutektische Reaktion (Schmelze <=> B-Gd2O3 + NiO) untersucht. Für das Gd-Sr-O System wurde ein thermodynamisches Modell aus Literaturdaten aufgestellt und auf Gd2O3-reichen Seite die Homogenitätsbereiche experimentell untersucht. Im Ce-Sr-Ni-O System wurde auf SrO-reichen Seite das Mischkristall (Ce,Sr)2NiO4-z untersucht. Es wurde festgestellt, dass keine Reaktion zwischen NiO und SrCeO3 / Sr2CeO4 stattgefunden hat. Im Ce-Gd-Ni-O System wurde keine Reaktion zwischen (Ce,Gd)O2-z und NiO gefunden. Im Ce-Gd-Sr-O System wurden Mischkristalle Sr(Ce,Gd)O3, Sr2(Ce,Gd)O4 und (Gd,Sr)2(Sr,Ce)O4 untersucht. Im Gd-Sr-Ni-O System wurde ein Mischkristall (Gd,Sr)2NiO4 untersucht, der in quasi-binären Schnitten nicht existiert, aber im System höherer Ordnung stabilisiert wird. Es wurde auch gefunden, dass in die Gd2SrO4 Phase keine NiO gelöst wird. Daraus kann man schliessen, dass dotierte Ceroxide (DC) basierte Materialien mit NiO während der Herstellung und Betrieb von IT-SOFC chemisch kompatibel sind, wobei LSGM Elektrolyte unter Herstellungsbedingungen in der Zelle mit NiO reagieren. Obwohl La2NiO4 eine Hochleistungskathode ist, lässt es sich nicht in Kombination mit LSGM oder DC benutzen, weil es mit den beiden Materialien unter Herstellungsbedingungen in der Zelle miteinander reagiert.

The energy expenditure (24h total energy expenditure, TEE) of a healthy individual or a patient is a vital reference point for nutritional therapy to maintain body mass. TEE is usually determined by measuring resting energy expenditure (REE) by indirect calorimetry or by estimation with the help of formulae like the formula of Harris and Benedict with an accuracy of ±20%. Further components of TEE (PAL, DIT) are estimated afterwards. TEE in intensive care patients is generally only 0–7% higher than REE, due to a low PAL and lower DIT. While diseases, like particularly sepsis, trauma and burns, cause a clinically relevant increase in REE between 40–80%, in many diseases, TEE is not markedly different from REE. A standard formula should not be used in critically ill patients, since energy expenditure changes depending on the course and the severity of disease. A clinical deterioration due to shock, severe sepsis or septic shock may lead to a drop of REE to a level only slightly (20%) above the normal REE of a healthy subject. Predominantly immobile patients should receive an energy intake between 1.0–1.2 times the determined REE, while immobile malnourished patients should receive a stepwise increased intake of 1.1–1.3 times the REE over a longer period. Critically ill patients in the acute stage of disease should be supplied equal or lower to the current TEE, energy intake should be increased stepwise up to 1.2 times (or up to 1.5 times in malnourished patients) thereafter. GMS German Medical Science; 7:Doc25; ISSN 1612-3174

Der vorliegende Kommentar wirft die Frage auf, ob die COVID-19-Pandemie als eine Generalprobe für das zu sehen ist, was uns in der bevorstehenden Klimakrise erwartet. Eine Vielzahl an Faktoren hat dazu beitragen, dass wir die Herausforderung der Corona-Pandemie aktiv bewältigen konnten und können. Hierzu gehören: die Integration von Wissenschaftlichkeit, der Einbezug von Medizinstudierenden, Lehre und Digitalisierung als Impulsgeber, Informationen über das SARS-CoV-2-Virus, deren Integration in die Curricula und nicht zuletzt eine handlungsbezogene Forschung. Die Klimakrise wird uns jedoch im Sinne einer „Premiere der Klima-Pandemie“ aller Voraussicht nach vor noch größere Bedrohungen und Schwierigkeiten stellen. Die Beachtung und Integration wissenschaftlicher Evidenz, die Lehre über die Auswirkungen der globalen Erwärmung, die bewusste Wahrnehmung ärztlicher Rollen- und Vorbildfunktionen sowie die Digitalisierung können dabei als Handlungsimpulse von besonderer Relevanz sein. In the present commentary, we raise the question whether the COVID-19 pandemic should be seen as just the dress rehearsal for what awaits us in the impending climate crisis. Many factors have helped us navigate the challenge of this coronavirus pandemic and continue to do so. These include: recognizing scientific expertise, medical education, and digitalization as important driving forces, providing us with key information about the SARS-CoV-2 virus, as well as integrating it into our curricula and promoting action-oriented research. However, the “premiere of the climate pandemic” will, in all likelihood, confront us with even greater challenges, difficulties, and threats. Adhering to scientific findings, promoting medical education about the effects of global warming and using the power of digitalization, as well as consciously engaging in our role as medical caregivers and leaders will make a decisive contribution to providing impetus for climate action. GMS Journal for Medical Education; 38(1):Doc29

This thesis is focused on the investigation and the identification of suitable non-aqueous electrolyte applied in the intermediate temperature polymer electrolyte fuel cells (IT-PEFCs). Herein, we show that protic ionic liquids (PILs) are the promising candidates for fuel cells operation in the temperature range of 100 °C to 120 °C. N,N-diethyl-N-methyl-3-sulfopropane-1-ammonium hydrogen sulfate [DEMSPA][HSA] and triflate [DEMSPA][TfO], N,N-diethyl-3-sulfopropane-1-ammonium hydrogen sulfate [DESPA][HSA] and triflate [DESPA][TfO] are investigated in this work. The physico-chemical properties relevant for IT-PEFC operations are systematically evaluated, including specific conductivity, thermal stability, viscosity, oxygen permeability and electrochemical properties. The triflate-based PILs provide the best combination of the fast oxygen reduction reaction (ORR) kinetics and fast oxygen transport. This applies in particular to [DESPA][TfO]. The physical-, electrochemical properties of non-stoichiometric [DESPA][TfO] are investigated. A series PIL blends are prepared, varying from an excess of the proton acceptor (N,N-diethyl-3-aminopropane-1-sulfonic acid) to an excess of the proton donor (triflic acid). The results show that an excess of the (free) acid is beneficial for the conductivity, oxygen reduction reaction (ORR) kinetics and the oxygen transmission coefficient. Blend membranes are prepared from polybenzimidazole (PBI) as a host polymer and stoichiometric and non-stoichiometric [DESPA][TfO] as the electrolyte. The PIL is immobilized in the PBI membrane by solution casting. The maximum PIL loading amount is determined based on the premise that the obtained blend membrane has a sufficient homogeneity, adequate thermal and mechanical stability and ionic conductivity. The blend membranes exhibit promising properties regarding an improved thermal stability and proton conductivity. The highest protonconductivity of 2 mScm-1 is achieved for PBI-PIL blends with stoichiometric [DESPA][TfO] and of 16 mScm-1 at 120 °C and 40% relative humidity for PBI-PIL blends with an excess acid respectively. Habilitationsschrift, RWTH Aachen University, 2022; Aachen : RWTH Aachen University 1 Online-Ressource : Illustrationen (2022). = Habilitationsschrift, RWTH Aachen University, 2022 Published by RWTH Aachen University, Aachen

All-solid-state lithium-ion batteries are considered a promising alternative to conventional liquid electrolyte-based lithium-ion batteries. The use of solid electrolytes could enable lithium metal as the anode material, which would lead to higher energy densities compared to conventional energy storage systems. At the same time, safety aspects could be improved by replacing highly flammable organic liquid electrolytes, making such systems particularly attractive for the mobility sector. Thiophosphate solid electrolytes are considered particularly promising in this context, as this materials class usually exhibits a high ionic partial conductivity and is suitable for conventional industrial manufacturing processes due to their advantageous mechanical properties (i.e., their malleability). However, large-scale application of all-solid-state lithium-ion batteries is currently still hindered by numerous problems. On the positive electrode side, interfacial reactions of the cathode active material with the thiophosphate solid electrolyte are considered to be one of the main reasons for rapid capacity loss of the battery and poor long-term stability. Detailed knowledge on such interfacial phenomena is scarce and studies on this subject are rarely differentiated, currently hindering a fundamental understanding and thus preventing a targeted solution to the problem. In this work, interfacial degradation phenomena in lithium thiophosphate- and LiNi0.6Co0.2Mn0.2O2-based composite cathodes were systematically investigated. It was shown that interfacial degradation occurs at all interfaces within the composite cathode. This includes interfacial reactions of the solid electrolyte against the (i) current collector, (ii) cathode active material, and, if used, (iii) carbon-containing conductive additive, which is often employed to enhance the electronic partial conductivity and to increase cathode active material utilization. By combining spectrometric and spectroscopic studies by means of time-of-flight secondary ion mass spectrometry and X-ray photoelectron spectroscopy, it was possible to separate the convoluted degradation processes and provide detailed insights into the reaction processes and the underlying chemistry. In addition, the reaction zones within the composite cathodes could be visualized based on local compositional information with high spatial resolution. Based on the knowledge gained, interfacial protection concepts were developed and investigated in this doctoral thesis. This includes protection concepts for carbon-based conductive additives and for cathode active materials. Analyses of a Li2CO3/LiNbO3-based coating on the cathode active material LiNi0.6Co0.2Mn0.2O2 showed that the protective effect can be attributed to the suppression of the interfacial reaction, in particular, of oxygenated phosphorus and sulfur compounds. Furthermore, it was possible to discuss the influence of the coating on the battery performance and the interfacial phenomena based on its microstructure (i.e., morphology and chemical composition). The results of this work extend the knowledge and understanding of interfacial degradation and corresponding protection concepts in composite cathodes. Such knowledge is essential for developing targeted protection concepts, overcoming problems related to interfacial degradation, and paving the way to long-term stability in all-solid-state lithium-ion batteries. The analytical approaches and workflows established in this doctoral thesis provide the foundation for future investigations on interfacial processes. Corresponding concepts can be transferred to other systems and material combinations, thus enabling the analytical characterization of protection concepts.

Rapid urbanisation in Ghana has resulted in individuals expanding the cities for abodes without considerations of the negative externalities these may have on the environment. One of the major challenges with rapid urbanisation is the formation of urban slums associated with lack of basic sanitation facilities. This has led to recurrent outbreak of cholera and typhoid fever. The use of a single-stage solar-supported hyper-thermophilic anaerobic biogas digester for the treatment of black water has not been investigated, hence this study. The performance of three seeding sludge under three different hyper-thermophilic temperatures (60°C, 65°C and 70°C) were tested in batch tests. The three seeding sludge were sewage sludge, sludge from maize silage and cow manure. The results from the batch tests showed cow manure at 65°C as the preferred seeding sludge and optimal hyper-thermophilic temperature. A 50 L single-stage laboratory-scale hyper-thermophilic continuous stirred tank reactor (HT-CSTR) was operated to treat only black water for 10 weeks using cow manure at 65°C as the seeding sludge and optimal hyper-thermophilic temperature. Afterwards, co-digestion of blended kitchen food waste and black water was also practised for 12 weeks. With a mean hydraulic retention time (HRT) of 23.3 days, a mean total COD removal of 86.3 % was achieved. The reactor had an average COD volumetric loading rate of 6.22 kgCOD/(m3.d) and remained uninhibited. It also had organic loading rate of 0.3 kgVS/(m3.d) and a degradation performance (R) of 5.43 kgCOD/(m3.d). Treatment of only black water produced biogas with less methane content of 34.9 % even though a stable pH of 6.9 was recorded both in the reactor and in the effluent. Co-digestion with kitchen food waste increased the percentage content of methane in the biogas by 77 % from 34.9 % to 61.8 %. The effectiveness of the HT-CSTR to hygienise the effluent for agricultural purpose was assessed by spiking the reactor with 200 ml each of 2 x 109 CFU/ml Salmonella senftenbergensis and 8 x 108 CFU/ml Escherichia coli. The HT-CSTR was able to hygienise all bacteria of Salmonella senftenbergensis and E. coli. A simulation test confirmed that between 30 minutes and 1 hour, all the cells of Salmonella senftenbergensis and E. coli in the treatment system were killed at 65 °C. Eubacteria, Methanosarcina spp., Methanomicrobium spp. and Methanococcus spp. were identified in the seeding sludge at the hyper-thermophilic temperature of 65°C. The design, construction and performance of a pilot-scale reactor in Terterkessim slum in Elmina, Ghana was based on results from the laboratory-scale HT-CSTR. It achieved 97 % removal of influent total COD and could produce about 2.52 Nm³CH₄/(kgCOD.d) which could be burned for at least 8 hours. The effluent cannot be used for cultivation of leafy vegetables such as cabbage since it had some concentrations of pathogens like Salmonella spp. and E. coli but can be used for cotton crop. Die schnelle und unkontrollierte Urbanisierung führt in vielen Städten Ghanas zur Vergrößerung der Bebauungsfläche für individuelle Unterkünfte ohne Berücksichtigung der negativen Effekte für die Umwelt. Eine der größten Herausforderungen der schnellen Verstädterung ist die Ausbildung von Slums, die nicht über eine grundlegende sanitäre Infrastruktur verfügen. Dies führt zu wiederkehrenden Ausbrüchen von Abwasser- und Fäkalienassoziierten Krankheiten wie Cholera und Typhus Fieber. Eine Möglichkeit der Abwasserbehandlung liegt in der Anwendung von einstufigen solar-geheizten hyperthermophilen anaeroben Bioreaktoren, die bisher jedoch nicht untersucht wurde. Daher liegt der Fokus dieser Arbeit in der Entwicklung eines solchen Reaktors in einem Modellstandort in Ghana, dem Terterkessim Slum, um Schwarzwasser und Gärreste zu desinfizieren und für die Landwirtschaft nutzbar zu machen und gleichzeitig Biogas herzustellen. Die Betriebseigenschaften von drei Inokulationsschlämmen wurden unter drei verschiedenen hyperthermophilen Temperaturen (60°C, 65°C und 70°C) nach der Richtline Verein Deutscher Ingenieure (VDI) 4630 (2006) in Batch-Ansätzen untersucht. Dabei handelt es sich um Belebtschlamm einer Kläranlage, Mais-Silage sowie Kuhdung. In den Batch-Ansätzen erwies sich Kuhdung bei 65°C am besten als Inokulationsschlamm geeignet, wenn optimale hyperthermophile Temperaturen und ein größerer Reaktor in Betracht kommen. In Gegenden ohne verfügbaren Kuhdung kann Klähranlagenschlamm bei 60°C alternativ als Inokulum verwendet werden.